How to shim a zenki factory oem (spring) lsd

[hachi_dk]

Car - ae86

motor - 20v ST

diff: Zenki T - series with OEM factory LSD

use - daily/track

problem - LSD started to single

occurs/started when - LSD started to single

so, i've taken apart my LSD and would like to shim it up.
as far as i know, you are suppose to "shim" or place washers under and/or above where the springs sit to give the springs more of a preload to improve the LSD's lock up characteristics?
i think thats generally how it works but would like someone to clear this up for me; as to what exactly i need to do

-i know that i can also purchase stiffer springs to also lower the amount of torque required so that the LSD locks up

-bear in mind this is the first time i've taken a diff apart and am going by common sense and also what i have heard.

any help is much appreciated!

regards, Fil.

[hachi_dk]

if i add in a washer that is the same size as one of the most outer clutch pack rings, (one on each side) will i have "shimmed" my LSD?

[sundee]

are u not going to rebuild the center while its out?

[hachi_dk]

yer i am, but i also want to make it reallllyyy tight. a step down from locker basically.
also, being a OEM factory LSD, even rebuilt it wont be that "harsh" in comparison to some aftermaket LSD's.
so, while its out i want to do the whole lot so i dont have to pull it out any time soon.

[s14seriesII]

why would you rebuild it unless its stuffed or noisey ? most ppl tend to make things worse when they 'rebuild' things

yes adding preload is a 'shimmed up' lsd but keep in mind that it will only have a higher break away point before it single spins, factory lsd's dont have an agressive enough ramp up to load the clutch plates/cones, etc so not enough lock from engine torque,

biggest problem is that the lsd is clearly not up to the task of being driven how it wasnt designed to, its half worn out, your going to shim it up so it will wear out 4 times quicker.

but sure find some stronger springs or add some washers into it, make sure you get the back lash and preload right when you put it back together, and dont leave the crownwheel bolts loose like other members on here have done

[hachi_dk]

thank you for your input.
im rebuilding it because it had started to single.

hmm, i understand what your saying about the factory LSD, i may have to just go a kaaz or cusco 2way.
i will rebuild and shim this one up and see how long that lasts me.

about 100rwkw is being put through the LSD so i think it should last me "long enough" and depending on how that goes, may just keep on rebuilding/shimming as a rebuild kit from t3 is about $200 which is pretty cheap.

[greeneyes]

Can you buy the clutch plates still? If it is slipping more than new its because the plates have worn thin and that has removed tension from the springs. Adding washers will restore the spring tension OK and make it lock more until the plate wear again.

I'm only familiar with Datsun LSDs which were one-ways without springs and just locked up under acceleration. The clutch pack slowly wore thin and lost their lock.

[hachi_dk]

yep thats what i thought.
seeing as im rebuilding with thicker clutch packs, i will be leaving in the centre thrust washer and also adding in the new one, so instead of the LSD originally having 3 clutch packs on each side, it will have 4.
its gonna be like a locker for the first month im guessing